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- cisco-sa-sb-lkm-zNErZjbZ
cisco-sa-sb-lkm-zNErZjbZ: Cisco IOS XR Software Secure Boot Bypass Vulnerability
First published: Wed Mar 12 2025(Updated: )
A vulnerability in the boot process of Cisco IOS XR Software could allow an authenticated, local attacker with high privileges to bypass the Secure Boot functionality and load unverified software on an affected device. To exploit this vulnerability, the attacker must have root-system privileges on the affected device.This vulnerability is due to insufficient verification of modules in the software load process. An attacker could exploit this vulnerability by manipulating the loaded binaries to bypass some of the integrity checks that are performed during the booting process. A successful exploit could allow the attacker to control the boot configuration, which could enable them to bypass the requirement to run Cisco-signed images or alter the security properties of the running system.Note: This vulnerability affects Cisco IOS XR Software, not the Secure Boot feature.Cisco has released software updates that address this vulnerability. There are no workarounds that address this vulnerability.This advisory is available at the following link:https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-sb-lkm-zNErZjbZThis advisory is part of the March 2025 release of the Cisco IOS XR Software Security Advisory Bundled Publication. For a complete list of the advisories and links to them, see Cisco Event Response: March 2025 Semiannual Cisco IOS XR Software Security Advisory Bundled Publication.
| Affected Software | Affected Version | How to fix |
|---|---|---|
| Cisco IOS XRv 9000 |
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Reference Links
Frequently Asked Questions
What is the severity of cisco-sa-sb-lkm-zNErZjbZ?
The severity of cisco-sa-sb-lkm-zNErZjbZ is classified as high due to the potential for bypassing Secure Boot functionality.
How do I fix cisco-sa-sb-lkm-zNErZjbZ?
To fix cisco-sa-sb-lkm-zNErZjbZ, upgrade Cisco IOS XR Software to the latest version provided by Cisco.
Who is affected by cisco-sa-sb-lkm-zNErZjbZ?
Authenticated, local users with high privileges on devices running affected versions of Cisco IOS XR Software are at risk from cisco-sa-sb-lkm-zNErZjbZ.
What could an attacker do with cisco-sa-sb-lkm-zNErZjbZ?
An attacker exploiting cisco-sa-sb-lkm-zNErZjbZ could load unverified software, compromising the integrity of the affected device.
What versions of Cisco IOS XR Software are affected by cisco-sa-sb-lkm-zNErZjbZ?
All versions of Cisco IOS XR Software that are susceptible to the vulnerability described in cisco-sa-sb-lkm-zNErZjbZ are at risk.
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